JPS63184739A - Inner latent image type silver halide photographic sensitive material - Google Patents

Abstract

PURPOSE:To obtain the stable positive image of the titled material by composing of a silver halide particle contd. in at least one layer of photographic constituting layers, in which the particle is composed of a core and at least one layer of a shell covering the core, and by incorporating silver chloride to the titled material as the surface composition of the shell. CONSTITUTION:The titled material is effected a surface development with a color developing solution which has <=1g/l the content of a solvent having >=0.4 log P and has low concentration of a sulfurous acid ion, after fog processing and/or during fog processing to obtain a color positive image. The silver halide particle contd. in at least one layer of the photographic constituting layers in said photosensitive material is composed of the core and at least one layer of the shell which covers the core, and the silver chloride is incorporated in the titled material, as the surface composition of the shell. The shell layer of the silver halide particle may be a single layer in the silver halide composition, or >=2 kinds of plural shell layers which have different silver halide compositions with each other. Thus, the stable photosensitive material, even in case of changing the condition of fog processing is obtd.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an internal latent image type silver halide photographic light-sensitive material,
In particular, the present invention relates to an internal latent image type silver halide photographic light-sensitive material that can provide a stable color positive image even against fluctuations in fogging during color development processing.

[Conventional technology]

In recent years, printing originals or versatile films have been used as originals, and after being imaged onto internal latent image type silver halide photographic light-sensitive materials using a copying machine, they are covered in a color developing solution and then developed to be printed directly on color photographic paper or color paper. It became possible to obtain positive images on film. For this reason, such copying devices have come to be installed in photo shops, copy shops, and the like.

However, in order to obtain stable and high-quality images through the photographic development processing described above, it is necessary to maintain the processing performance of the processing liquid at a constant state. Therefore, when a large amount of light-sensitive material is subjected to processing such as color development, each processing solution is used up and deteriorates. Complementary or inferior.

It is necessary to restore the activity of the degraded processing solution with a replenisher to maintain the initial activity and perform stable processing. In particular, when replenishing degraded processing liquid, the processing liquid will naturally overflow and be recovered as waste liquid. The collected waste liquid may contain harmful components or components undesirable from the viewpoint of pollution prevention, and therefore, it is necessary to first detoxify the waste liquid before it can be disposed of.

In this way, it requires a great deal of cost and labor to detoxify and dispose of harmful components in the processing solution.
The above-mentioned organic solvents have high BOD and COD values, and it is desired to reduce the amount used or not use them at all.

However, if the amount of organic solvents such as benzyl alcohol used is minimized or color development is performed without using them, the oxidized product of the color developing agent produced by the color development reaction becomes a compound that reacts with the coupler of the light-sensitive material. There is a problem in that it preferentially reacts with sulfite ions used as antioxidants in the color developing agent in the developer, rather than with the reaction, resulting in a decrease in image density.

As a solution to this problem, it is effective to reduce the concentration of sulfite ions to enhance the coupling reaction. However, when processing using a color developing solution with a low concentration of sulfite ions, there is a problem in that images vary greatly due to changes in processing conditions. A photosensitive material containing internal latent image type silver halide grains consisting of a silver shell has a problem in that a positive image tends to fluctuate due to fluctuation factors during fogging.

In other words, when fogging is caused by light, the illuminance of the fogging light is due to deterioration of the light source, or the amount of exposure on the photosensitive surface is reduced due to the filter effect due to oxidation coloring of the color developer. When fogging occurs, the concentration of the fogging agent decreases due to air oxidation and the like. In particular, the maximum density of the obtained image may be significantly reduced due to the above-mentioned fluctuation, which is a problem.

Therefore, as a technique for suppressing the decrease in image density, it has been reported that the surface of silver halide grains is subjected to chemical ripening to some extent (US Pat. No. 3,761,276), but this is not always satisfactory.

[Purpose of the invention]

The first object of the present invention is to provide an internal latent image type silver halide photographic light-sensitive material that can stably obtain a positive image, and secondly, it can be processed with a processing liquid that causes less pollution from waste liquid. An object of the present invention is to provide an internal latent image type silver halide photographic material.

[Structure and operation of the invention]

In the present invention, the content of the solvent with logP of 0.4 or more is Ig
/j! In the following, an internal latent image type silver halide photographic sensitizer that can obtain a color positive image by performing surface development processing after fogging treatment with a color developing solution having a low sulfite ion concentration and/or while performing fogging treatment. A material in which the silver halide grains contained in at least one of the photographic constituent layers of the light-sensitive material consist of a core and at least one shell covering the core, and the surface composition of the shell contains at least silver chloride. The above object could be achieved by obtaining an internal latent image type silver halide photographic light-sensitive material containing the following.

In the photographic material of the present invention, the silver halide grains contained in at least one of its photographic constituent layers consist of a core and at least one shell covering the core, and the shell contains at least silver chloride as a surface composition. are doing. The silver halide grains only need to substantially contain silver chloride as the surface composition of their shells, and even if the surface composition is silver chloride,
Alternatively, silver chloride may be contained in the form of silver chlorobromide, silver chloroiodobromide, silver chloroiodide, or the like. In a preferred embodiment, the content of silver chloride in the surface composition is 50 mol% or more.

The silver chloride-containing portion on the surface of the shell layer of the silver halide grain may be the entire surface of the silver halide grain,
In the present invention, the surface layer containing silver chloride of the shell preferably occupies 10% or more of the surface area of the grain surface.

The shell in the silver halide grains may be a single layer having a single silver halide composition, or may be a multilayer shell having two or more layers having different silver halide compositions.

In the case of a multilayer shell, it consists of at least an outermost layer and a layer adjacent to it, but it may also have a structure in which layers having different silver halide compositions are distinctly separate layers and are laminated. Further, the multilayer shell does not necessarily have a layer structure in which the layers are distinctly separate layers, but may have a structure in which the silver halide composition changes continuously in the radial direction of the silver halide grains.

In the case of the above-mentioned multi-layer shell, if silver chloride is contained in the outermost layer of the multi-layer shell, or at least its surface, or the surface layer of the shell of the layer adjacent to the outermost layer, the entire particle or the inner layer is The silver halide composition of the whole grain or the inner layer may have a silver halide composition such as, for example, silver iodobromide, silver bromide, silver chlorobromide, silver chloroiodide, silver chloroiodobromide. Silver is an example. Silver halide containing silver chloride is preferred, and silver chloride content is preferably 50 mol % or more in terms of the surface composition of the grains.

It is preferable that the shell covers 50% or more of the surface area of the core, and it is particularly preferable that the shell completely covers the core.

The core preferably mainly consists of silver bromide and may further contain silver chloride and/or silver iodobromide. The silver halide grains forming the core may have any shape, for example, The particles may be cubic, octahedral, dodecahedral, tetradecahedral, or a mixture thereof, or may be spherical, tabular, irregularly shaped particles, or an appropriate mixture of these. In carrying out the present invention, the average particle size and particle size distribution of the silver halide grains constituting the core can be varied over a wide range depending on the desired photographic performance, but a narrower particle size distribution is more preferable.

That is, the silver halide grains constituting the core are preferably substantially monodisperse.

Here, silver halide grains with a monodisperse core mean that the weight of silver halide grains contained within a grain size range of ±20% around the average grain size F in the silver halide grains constituting the core is total halogen. 60% or more of the weight of silver oxide,
Preferably it is 70% or more, particularly preferably 80% or more.

Here, the average particle size F is the frequency rl of particles having particle size r.
The product n(xrt) of i, r, and 3 means the maximum particle size r! (3 significant figures, minimum number of digits is 4 to 5).

In addition, the grain size here refers to the diameter in the case of spherical silver halide grains, and in the case of grains with shapes other than spherical, the diameter when the projected image is converted into a circular image with the same area. It is.

The particle size can be obtained, for example, by magnifying the particle 10,000 to 50,000 times with an electron microscope and projecting it, and actually measuring the particle diameter or area at the time of projection on the print (the number of particles measured is Suppose there are more than 1000 items indiscriminately.)

Examples of methods for producing the monodisperse core emulsion include, for example, Japanese Patent Publication No. 4B-36890, Japanese Patent Application Laid-open No. 48520/1986,
The double jet method disclosed in various publications such as No. 54-65521 can be used. In addition, JP-A-54-15
A premix method described in Japanese Patent No. 8220 and the like can also be used.

In carrying out the present invention, the core of the silver halide grains is chemically sensitized, doped with metal ions, or both, or not at all. It may be.

As chemical sensitization, sulfur sensitization, gold sensitization, reduction sensitization, noble metal sensitization, and combinations of these sensitization methods can be employed. As the sulfur aggravating agent, thiosulfates, thioureas, thiazoles, rhodanines, and other compounds can be used. Such methods are described, for example, in U.S. Pat. No. 1.574.944, U.S. Pat. No. 1.623.499, U.S. Pat. The core of the silver halide grains used in carrying out the present invention is disclosed in, for example, U.S. Pat.
．． As described in No. 597.856, No. 2.642.361, etc., sensitization can be carried out with a water-soluble gold compound, and sensitization can also be carried out with a reduction sensitizer.
Such methods are described, for example, in U.S. Pat.
7.850, 2.518.698, 2.9
83°610, etc. can be referred to.

Furthermore, noble metal sensitization can also be carried out using noble metal compounds such as platinum, iridium, palladium, and the like. Such methods are described, for example, in U.S. Pat.
48.060 and British Patent No. 618.061.

Also, the core of the silver halide grains can be doped with metal ions. To dope the core with metal ions,
For example, it can be added as a water-soluble salt of the metal ion during any process of forming the core particle. Preferred specific examples of metal ions include metal ions such as iridium, lead, antimony, bismuth, gold, osmium, and rhodium. These metal ions are preferably silver 1
A concentration of 1X10-'' to 1X10-' molar to molar is used.

However, the core of the silver halide grains may not be subjected to the above-mentioned chemical sensitization treatment or metal ion doping. In this case, it is thought that photosensitive centers are generated by forming crystal strain at the interface between the core and shell during the process of covering the core particle with a shell, and this is discussed in US Pat. Reference may be made to the descriptions in .935°014 and 3,957.488.

A double jet method or a premix method can be used to form the shell on the core described above. It is also possible to form the core emulsion by mixing fine grains of silver halide and performing Ostwald ripening.

As described above, by making the halogen particles into a core/shell type and including silver chloride in the surface composition,
By effectively performing fogging processing, the maximum density of the obtained image can be increased, and a stable image of good quality can be obtained.

Further, the content of silver chloride in the silver halide grains is not particularly limited, but in order to meet the demand for shortening processing time, it is preferable to use silver halide grains with a high content of silver chloride. .

In such embodiments, the silver chloride content is preferably at least 50 mole %, more preferably at least 80 mole % of the total amount of silver halide in the grains.

Another preferred embodiment of the present invention is an embodiment in which a heterocyclic compound having a mercapto group is contained in the light-sensitive material. In particular, when producing a photosensitive material containing silver halide with a high content of silver chloride as mentioned above, by using a heterocyclic compound having a mercapto group, even better positive images can be obtained and the effect It is true.

When carrying out the above embodiment, the heterocyclic compound having a mercapto group can be contained in any photographic constituent layer of the light-sensitive material.

As the heterocyclic compound having a mercapto group, a compound represented by the following general formula CI) is preferable.

General Formula (1) In the formula, M represents a hydrogen atom, an alkali metal atom, an ammonium group, or a protecting group for a mercapto group, and Z represents a group of nonmetallic atoms necessary to form a heterocycle. The heterocycle may have a substituent or be fused.

The protecting group for the mercapto group represented by M is a group that forms a mercapto group when cleaved with an alkali, and specific examples include an acyl group, an alkoxycarbonyl group, and an alkylsulfonyl group.

Atom, nitrogen atom, oxygen atom, sulfur atom, selenium atom, etc. may be included as a ring-constituting atom, and a 5- to 6-membered ring is preferable.

Specific examples of heterocycles include imidazole, benzimidazole, na-phthoimidazole, thiazole, thiazoline, benzothiazole, naphthothiazole, oxazole, benzoxazole, naphthoxazole, selenazole, benzoselenazole, naphthoselenazole, triazole, benzotriazole. , tetrazole, oxadiazole, thiadiazole, pyridine, pyrimidine, triazine, purine, azaindene and the like.

Examples of substituents that these heterocycles may have include halogen atoms, hydroxy, amino, nitro, mercapto, carboxy and salts thereof, sulfo and salts thereof, alkyl, alkoxy, aryl, aryloxy, alkylthio, arylthio, acylamino , sulfonamide, carbamoyl, sulfamoyl and the like.

Among the compounds represented by the general formula (1), particularly preferably used compounds are the following general formulas (n), (III) and (
IV).

General formula (n) General formula (I[[) General formula (IV) In general formulas (II) to (TV), M is general formula (1)
It is synonymous with M in .

In the general formula ([), Ar represents a phenyl group, a naphthyl group, or a cycloalkyl group, and R1 represents a hydrogen atom or a substituent of Ar.

In the general formula (II[), zl represents an oxygen atom, a sulfur atom, a selenium atom, or -NH-, and e represents a hydrogen atom or a substituent.

-a In formula (IV), Zz oxygen atom, sulfur atom,
Selenium atom or -N- (R' is a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, an aralkyl group, -COR', -5OtR').

-NHCOR' or -NHSO,R'', R5 represents an alkyl group, aryl group, aralkyl group or amino group, R6 represents an alkyl group, cycloalkyl group, aryl group or aralkyl group), and R2 represents Represents a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, an aralkyl group, a heterocyclic group, or an amino group.

Typical specific examples of the compound represented by the general formula (I) are listed below, but the present invention is not limited thereto.

■ (17) (1B
) HII The above compound can be easily synthesized by a known method. For example, U.S. Patent No. 2,403.927;
, No. 376.310, JP-A-55-59463 or Journal of the Chemical Society, (
J.

Chem, Soc, ) + 1952, p. 4237. Moreover, some compounds are available as commercial products.

The above-mentioned compounds can be dissolved in water or an organic solvent having an affinity for water, such as methanol, acetone, etc., or dissolved in a weak alkali or weak acid, and then added to the light-sensitive material element.

The amount added may vary depending on the type of compound used and the layer to which it is added. Generally, when added to a silver halide emulsion layer, the amount added is 101 per mol of i1 halide.
In the range of mol or more and less than 10-3 mol, more preferably 1
The range is 0-5 mol or more and less than 10" 3 mol.

Heterocyclic compounds having a mercapto group can be used in any of the constituent layers of ordinary photosensitive materials, such as the silver halide emulsion layer of photosensitive materials, protective layers, intermediate layers, filter layers, antihalation layers, and undercoat layers. Although it may be added to any layer, a particularly preferred layer is a silver halide emulsion layer.

Next, the internal latent image type silver halide used in the present invention will be described.

In order to widen the exposure latitude of the internal latent image type silver halide used in the present invention, emulsions having different sensitivities can be stacked or mixed as emulsion layers.

In this case, the ratio of the amount of coated silver in each emulsion layer can be arbitrarily determined depending on the required photographic properties.

In the present invention, internal latent image type silver halide grains which are not fogged in advance can be used as the internal latent image type silver halide grains. In this case, the meaning that the particle surface is not fogged in advance means that a test piece coated with the emulsion to be used on a transparent film support at a concentration of 35 mgAg/cts was treated with the following surface developer A without being exposed. 20
This means that the density obtained when developed for 10 minutes at °C does not exceed 0.6, preferably 0.4.

Surface developer A Metol 2.5 g 1-ascorbic acid 10 g NaB Ot・
4 H! O35g KBr
Add 1 g of water. 11 Furthermore, as the silver halide emulsion used in the silver halide emulsion layer for forming a color positive image in the light-sensitive material of the present invention, the internal latent image which is not fogged in advance and which is prepared as described above is used. A test piece of the photosensitive material of the present invention containing type silver halide grains is preferably used, which gives sufficient density when developed with internal developer B having the following formulation after exposure.

Internal developer B Metol 2g Sodium sulfite (
Anhydrous) 90g Hydroquinone 8g Soda carbonate (-water salt) 52.5 gKBr
5 gKI
O, add 5g water
11 More specifically, a portion of the specimen described above was exposed to a light intensity scale for a defined period of time up to about 1 second, and then treated with internal developer B at 20°C for 10 minutes.
at least 5 times, preferably at least 10 times, when developed for 10 min, a maximum It indicates the concentration.

Silver halide emulsions that can be used in carrying out the present invention can be optically sensitized with commonly used sensitizing dyes. The combination of sensitizing dyes used for supersensitization, such as internal latent image type silver halide emulsions and negative silver halide emulsions, also applies to the silver halide emulsions used in carrying out the present invention. Useful. Regarding sensitizing dyes, please refer to Research Disclosure (Resea).
rchDisclosure) No. 15162 and No. 17643.

In order to directly obtain a positive image using the photosensitive material of the present invention, a positive image can be easily obtained by performing image exposure (shading) and then surface development. That is, the main process of creating a positive image is to apply a photographic material having an internal latent image type silver halide opalescence layer that is not fogged in advance, which is applied to the present invention, to a chemical or optical action after image exposure. This process involves performing surface development after and/or while performing a process for generating fog nuclei, that is, a process for forming a fog. Here, the fogging treatment can be carried out using a compound that provides full exposure or generates fogging nuclei, that is, a fogging agent.

The entire surface exposure of the photographic light-sensitive material of the present invention is carried out by immersing or moistening the image-exposed light-sensitive material in a developer or other aqueous solution, and then exposing the entire surface uniformly to light. The light source used here may be any light within the sensitive wavelength range of the above-mentioned photographic light-sensitive materials, and high-intensity light such as flash light can be applied for a short time, or weak light can be applied for a long time. good. Further, the total exposure time can be varied over a wide range depending on the photographic material, development processing conditions, type of light source used, etc. so as to ultimately obtain the best positive image. Further, it is most preferable that the exposure amount for full-surface exposure is within a certain range in combination with a photosensitive material. usually,
Excessive exposure causes an increase in minimum density and desensitization, resulting in a decrease in image quality, but when the photosensitive material of the present invention is used, the degree of image quality deterioration is reduced and stable images can be obtained. .

Next, a fogging agent that can be used in chemically fogging the photographic light-sensitive material according to the present invention will be described. A wide variety of compounds can be used as the fogging agent used in carrying out the present invention, and the fogging agent only needs to be present during the development process. It may be contained in a layer (among them, a silver halide emulsion layer is particularly preferred), or in a developer or a processing solution prior to wart development. The amount used can vary widely depending on the purpose, and the preferred amount is 1 to 1.50 per mole of silver halide when added to a silver halide emulsion layer.
0 mg, preferably 10 to 1,000 μg. Also, when added to a processing solution such as a developer, the preferred amount is 0.01 to 5 g/l, particularly preferably 0.05 to 1 g/l.
It is l.

Examples of fogging agents used in the present invention include hydrazines described in U.S. Pat. No. 2,563,785 and U.S. Pat.
27.552; U.S. Patent No. 3.615.615;
No. 718.479, No. 3.719.494, No. 3
．． Heterocyclic quaternary nitrogen salt compounds described in US Pat. No. 734.738 and US Pat. No. 3,759.901;
．． Examples thereof include compounds having an adsorption group on the silver halide surface, such as acylhydrazinophenylthioureas described in No. 030.925. These fogging agents can also be used in combination. For example, Research Disclosure
e) No. 15162 describes the use of a non-adsorption type fogging agent in combination with an adsorption type fogging agent, and this combination technique is also effective in the present invention. Both adsorption type and non-adsorption type can be used, and they can also be used in combination.

Developers that can be used in the surface developer for developing the photographic material of the present invention include common silver halide developers, such as polyhydroxybenzenes such as hydroquinone, aminophenols, 3-pyrazolidones, Contains ascorbic acid, its derivatives, reductones, phenylenediamines, etc., or mixtures thereof.

Specifically, hydroquinone, aminophenol, N-methylaminophenol, 1-phenyl-3-pyrazolidone, 1-phenyl-4,4-dimethyl-3-pyrazolidone, 1-phenyl-4-methyl-4-hydroxymethyl- 3-pyrazolidone, ascorbic acid, N,N-diethyl-p-phenylenediamine, diethylamino-0-)
Luidine, 4-amino-3-methyl-N-ethyl-N-
(β-methanesulfonamidoethyl)aniline, 4-
Examples include amino-3-methyl-N-ethyl-N-(β-hydroxyethyl)aniline. It is also possible to include these developers in advance in the emulsion and allow them to act on the silver halide during immersion in the high pH aqueous solution.

The developer used in the present invention can further contain specific antifoggants and development inhibitors, or these developer additives can be optionally incorporated into the constituent layers of the photographic material. be.

When implementing the photosensitive material of the present invention for full color use,
At least one layer each of a red malignant silver halide emulsion layer, a green-sensitive silver halide emulsion layer, and a blue-sensitive silver halide emulsion layer are coated on the support as photographic constituent layers. In this case, at least one photosensitive silver halide emulsion layer contains core/shell type grains including a core and at least one shell covering the core, and contains silver chloride as a surface composition of the shell. Of course, it is preferable that all the photosensitive silver halide emulsion layers contain the internal latent image type silver halide grains of the present invention. Each photosensitive silver halide emulsion layer may be the same photosensitive layer or may be separated into two or more layers having different sensitivities; in this case, at least one
It is sufficient if the photosensitive layers having different sensitivities contain the internal latent image type silver halide grains according to the present invention, but all emulsion layers contain the internal latent image type silver halide grains according to the present invention. It is preferable that it contains.

The color developing solution used in the photosensitive material of the present invention will be explained. The color developing solution has a content of a solvent having a logP of 0.4 or more of Ig/f or less, and a low concentration of sulfite ions.

The above 1ogP is a value determined from the partition coefficient P of n-octatool/water. The P value can be determined using the following formula. The logarithm of the P value thus determined is the solute concentration log P value in the aqueous phase, and this value is a value of 1 that has been widely used in the field of agrochemicals and medicines as a measure of lipid solubility.

The logP value is determined by “Chemical Review (ChemicalR)
viewJ magazine, 1971, Vol. 71, No. 6, pp. 555-61
It can also be determined by the log P oct in the table described on page 3. For example, ``Ecochemistry'' Vol. 6, 3
Although it can be determined theoretically by the calculation method described on pages 1 to 11, it is preferable to use actually measured values, and it is particularly preferable to use values measured using an n-octatool.

Solvents with a log P of 0.4 or more that are not preferably added to the developer used in the photosensitive material of the present invention include aliphatic alcohols, aliphatic glycol ethers, alicyclic alcohols, and aromatic alcohols. Among these, those having 5 to 20 carbon atoms.

As a specific example, benzyl alcohol logP 1.10
0-hydroxybenzyl alcohol logP 0.73 cyclohexanol logP 1.23
2-benzyloxyethanol 1 layer gP O,41 anisyl alcohol logP 0.701-
Pentanol 1 layer gP O, 4 or more Phenylethyl alcohol 1 layer gP 1.36p-
) Lyrucarbinol logP 1.36 Phenol 1 layer gP O, 4 or more p
-Hydroxybenzyl alcohol logP 0.4 or more Benzylamine logP O, 4 or more diethylene glycol monobutyl ether log P
0.41 etc.

As described above, the solvent is a compound that promotes the coupling reaction between the oxidized color developing agent and the coupler of the light-sensitive material, and its content is set to 1 g/l or less. By reducing the concentration to such a low level, even when the deteriorated color developing solution is discarded, the BOD and COD values can be kept low, which is effective in terms of pollution control. Furthermore, by reducing the concentration of sulfite ion as a preservative, the reaction with the above-mentioned solvent is suppressed, and the campling reaction in color development processing is enhanced.

In the present invention, the low sulfite ion concentration refers to a concentration of preferably 2.times.10"" mole or less per color developer 11, more preferably a concentration of 1.times.10" mole/1.

As mentioned above, since the coupling reaction is effectively carried out by reducing the sulfite ion concentration, the color image developed by the color developing solution has a high maximum density and a good image can be obtained.

In addition, the bromine ion concentration in the color developer is
Preferably, it is not more than 5×10 −3 mol per mol.

In the present invention, the low concentration of sulfite ions in the color developing solution as described above is combined with the fact that the surface composition of the internal latent image type silver halide grains is a core/shell grain containing silver chloride. This results in a photosensitive material that is stable against fogging and has excellent image quality.

〔Example〕

Next, the present invention will be specifically explained with reference to Examples.

However, it goes without saying that the embodiments of the present invention are not limited to the embodiments illustrated below.

Example-1 Equimolar silver nitrate aqueous solution and potassium bromide aqueous solution were heated at 50°C.
By simultaneously adding them for about 40 minutes using the Chondrald double jet method, a tetradecahedral silver bromide emulsion with an average grain size of 0.4 μm was obtained. However, 5 minutes after starting the addition of silver nitrate aqueous solution and potassium bromide aqueous solution, 0.0.
02111r potassium to hexachloride resort was added. 2 per mole of silver in the emulsion thus obtained.
．． Emulsion A was obtained by adding 0 ml of sodium thiosulfate and chemical ripening at 60° C. for 60 minutes.

Using this emulsion A as a core particle, a core/shell type emulsion BE shown below was obtained.

Emulsion B: Emulsion A was used as a core particle, and a silver nitrate aqueous solution and a potassium bromide aqueous solution were added simultaneously to obtain an average particle size of 0.6.
A 14 μm tetradecahedral core/shell type emulsion was obtained.

Emulsion C: Using Emulsion A as a core grain, a silver nitrate aqueous solution and a potassium bromide aqueous solution are added simultaneously to grow the grains to a size of 0.5 μm.Subsequently, a silver nitrate aqueous solution and a sodium chloride aqueous solution are simultaneously added to obtain an average grain size of 0. A cubic core/shell type emulsion with a .6μ ring was obtained.

Emulsion D: A core/shell emulsion was obtained in substantially the same manner as Emulsion C above. However, the emulsion contains potassium bromide and sodium chloride (KB in molar ratio) instead of the sodium chloride aqueous solution.
It was prepared by adding an aqueous solution containing r:NaCl=1=3).

Emulsion E: Core/shell emulsion E was obtained in substantially the same manner as emulsion C above. However, the emulsion E contains potassium bromide and sodium chloride (K in molar ratio) in place of the aqueous sodium chloride solution.
Br:NaCj! -1: Prepared by adding an aqueous solution containing 1).

Emulsion F: Core/shell emulsion F was obtained in the same manner as emulsion C above. However, the emulsion F contains potassium bromide and sodium chloride (KBr:NaC in molar ratio) instead of sodium chloride.
It was prepared by adding an aqueous solution containing 1=1:1).

Each of emulsions B-F obtained above had 5.5 sensitizing dyes.
'-diphenyl-9-ethyl-3,3'-disulfopropyloxacarbocyanine sodium salt and 1-(2,4,6-dolichlorophenyl)-3-(2-chloro-5-octadecyl as magenta coupler) A dispersion of succinimide anilino)-5-pyrazolone dissolved in a solvent and emulsified in an aqueous gelatin solution was added, and a hardening agent was further added to the resin-coated paper support so that the amount of silver coated was 4 /
100cm” and dried, sample 11hl
~5 was created.

Each of these samples was wedge exposed through a yellow filter and developed for 3 minutes at 38° C. with a developer having the following formulation.

However, the entire surface was uniformly exposed to white light at the exposure amount shown in Table 1 below for 20 seconds after the start of development, followed by bleach-fixing, washing with water, and drying in a conventional manner. Thereafter, the sample Na
~5 was developed.

As is clear from the results in Table 1, by including silver chloride in the surface composition of the outermost shell layer of the core/shell particles according to the present invention, the maximum density is significantly improved, and the fogging exposure is It can be seen that this is a stable and good positive image.

Furthermore, the sodium sulfite concentration of the color developing solution is changed from the low concentration I
It can be seen that when changing to 0-''M/1, the maximum density of the obtained image decreases rapidly.

Therefore, it can be seen that the photosensitive material of the present invention provides an image with a high maximum density when the sulfite ion concentration is in the low concentration range.

Example 2 Equimolar amounts of a silver nitrate aqueous solution and a potassium bromide aqueous solution were added and mixed at 50° C. by a simultaneous mixing method to obtain a silver bromide emulsion G having 0.4 μ tetradecahedrons.

Using this emulsion G as core grains, a core/shell type emulsion HL as shown below was obtained.

Emulsion H: Using the above emulsion G as a core particle, a silver nitrate aqueous solution and a potassium bromide aqueous solution were added simultaneously to obtain an average particle size of 0.
．． A 6 μm tetradecahedral core/shell type emulsion was obtained.

Emulsion I: Using the above emulsion G as core particles, a silver nitrate aqueous solution and a sodium chloride aqueous solution were added simultaneously to obtain an average particle size of 0.6μ.
- A cubic core/shell type emulsion was obtained.

Emulsion J: Core/shell emulsion J was obtained in substantially the same manner as emulsion I above. However, Emulsion J contains potassium bromide and sodium chloride (KB in molar ratio) in place of the aqueous sodium chloride solution.
r:NaCjt-1: prepared by adding an aqueous solution containing 4).

Emulsion: Core/shell emulsion K was obtained in substantially the same manner as emulsion I above. However, the emulsion contains potassium bromide and sodium chloride (KB in molar ratio) instead of the sodium chloride aqueous solution.
r:NaCj! =1: Prepared by adding an aqueous solution containing 1).

Emulsion L: A core/shell emulsion was obtained in substantially the same manner as the above emulsion ①. However, the emulsion contains potassium bromide and sodium chloride (KBr:N in molar ratio) instead of sodium chloride.
aCj! =4: Prepared by adding an aqueous solution containing 1).

A sensitizing dye represented by the following formula was added to each of the above emulsions HL.

In addition, as a cyan coupler, 2,4-dichloro-3-methyl-6-[α-(2,4-di-tert-aminophenoxy)butyramide]phenol was dissolved in diptylphthalate and ethyl acetate and dispersed in an aqueous gelatin solution. A liquid was prepared.

Next, the emulsified dispersion was added to each emulsion containing the sensitizing dye and mixed, and a hardener was added so that the amount of coated silver was 5.0 μ/10.
Samples 1h6 to 10 were prepared by applying the coating onto a resin-coated paper support to a thickness of 0 cm'' and drying it.

Each of these samples was wedge exposed through a yellow filter and developed for 3 minutes at 38° C. with a developer having the following formulation.

Table 2 below shows the results of measuring the maximum and minimum densities of cyan positive images of each sample obtained by bleach-fixing, washing with water, and drying using a conventional method.

As is clear from the results in Table 2, by including silver chloride in the surface composition of the outermost layer of the shell of the core/shell particles of the present invention, the maximum concentration is significantly improved, even when the fogging agent concentration varies. It can be seen that good positive images with high maximum density can be stably obtained.

L:,,,,nee;;.

Example 3 Equimolar amounts of a silver nitrate aqueous solution and a potassium bromide aqueous solution were added and mixed at 50° C. by a simultaneous mixing method to obtain an emulsion M of cubic silver bromide grains of 0.2 μm.

Using this emulsion as a core particle, equimolar silver nitrate aqueous solution and sodium chloride aqueous solution were added at the same time, and the average particle size was 0.7.
A core/shell type emulsion N having cubic grains of μm size was obtained (silver chloride content: 98 mol%).

α-(4
-(1-benzyl-2-phenyl-3゜5-dioxo-
1,2,4-)riazolidinyl)]-]α-bivalyl-2-chloro5-Cr-(2゜4-di-tert-
A dispersion of amylphenoxy)butyramide]acetanilide dissolved in a solvent and emulsified and dispersed in an aqueous gelatin solution was added, and a hardening agent was added to the resin-coated paper support so that the coated silver amount was 6 g/100-. A sample was prepared by coating and drying. Further, a specific example Ni1 (3
) was added to the emulsion, and a sample was prepared in exactly the same manner as in Example 2 except for that.

Each of these samples was exposed with a wedge, and a developer with the following formulation was used for 3
Developed at 8°C for 1 minute.

(The pH was adjusted to 10.2 with sodium hydroxide.) However, 10 seconds after the start of development, the entire surface was uniformly exposed to white light at various exposure amounts shown in Table 3, and then bleached and fixed using the usual method. , washed with water, and dried.

As is clear from the results in Table 3, by processing the light-sensitive material containing emulsion K of core/shell grains according to the present invention with the above-mentioned color developing solution that does not contain benzyl alcohol and has a low sulfite ion concentration. A good positive image can be stably obtained even with variations in the exposure amount of Capri exposure (sample m1l). Further, by using a heterocyclic compound having a mercapto group in combination, the minimum concentration is suppressed, so that the positive image is further improved (Sample No. 12).

Note that when a large amount of a heterocyclic compound having a mercapto group is contained, as in sample No. 13, the effect is that it is stable against changes in exposure and the minimum concentration is small, but the ignition concentration decreases. There is a tendency. (Regarding the inclusion of a large amount of a heterocyclic compound having a mercapto group, see Table 3 of Japanese Patent Publication No. 45-12709. [Effects of the Invention] As described above, according to the present invention, the maximum density of a positive image obtained by color development is high. Moreover, it is possible to obtain an internal latent image type silver halide photographic light-sensitive material that is stable even against changes in fogging processing conditions.

Moreover, it is possible to obtain an internal latent image type silver halide photographic light-sensitive material that can obtain the above-mentioned high-quality images even when processed with processing liquids with low pollution loads such as BOD and COD.

Claims (1)

[Claims] 1. Surface development treatment is performed after and/or while performing fogging treatment with a color developer with a logP of 0.4 or more, a content of 1g/l or less of a solvent, and a low sulfite ion concentration. An internal latent image type silver halide photographic light-sensitive material capable of obtaining a color positive image, the silver halide grains contained in at least one of the photographic constituent layers of the light-sensitive material comprising a core and at least one layer covering the core. 1. An internal latent image type silver halide photographic light-sensitive material comprising a single-layer shell, the shell containing at least silver chloride as a surface composition.